Brandon is 4 times as old as Kevin and is also 12 years older than Kevin. How old is Brandon?
Answer: We can use the given information to write down two equations that describe the ages of Brandon and Kevin. Let Brandon's current age be $b$ and Kevin's current age be $k$ $b = 4k$ $b = k + 12$ Now we have two independent equations, and we can solve for our two unknowns. One way to solve for $b$ is to solve the second equation for $k$ and substitute that value into the first equation. Solving our second equation for $k$ , we get: $k = b - 12$ . Substituting this into our first equation, we get the equation: $b = 4$ $(b - 12)$ which combines the information about $b$ from both of our original equations. Simplifying the right side of this equation, we get: $b = 4b - 48$ Solving for $b$ , we get: $3 b = 48$ $b = 16$.